This invention relates in general to a seat track assembly for a vehicle, and in particular to a seat track assembly that includes a roller assisted frictional element for assisting motion in the fore and aft direction as well as for providing impact and load dampening characteristics.
Most vehicle seats, particularly in passenger vehicles, are generally provided with adjustment mechanisms to allow a seat occupant to position the seat for optimal comfort and convenience. A vehicle seat typically includes a seat back that is mounted with a seat bottom. Many vehicle seats also include a recliner mechanism to adjust the angle of the seat back relative to the seat bottom. Vehicle seats can also include mechanisms that allow movement of the seat forward and backward (fore and aft) relative to the floor of the vehicle. To accomplish this, vehicle seats are mounted on a seat support frame that is mounted on first and second spaced apart track assemblies. Each assembly has an upper track connected to the seat support frame that is slidably mounted on a lower track that is fixed to the vehicle floor. The seat track assembly generally also includes an element disposed between the upper and lower track that facilitates the sliding movement between the upper and lower tracks. Sliding elements using various rolling elements, such as roller bearings or ball bearings, are known in the prior art. Sliding elements including a low-friction member between the tracks are also known.
Over time, the forces exerted on the vehicle seat cause uneven wearing of conventional seat track assemblies. Specifically, small indentations or bumps from the rolling elements can form on the upper and lower tracks of the seat track assembly, especially when the rolling elements are left at the same position along the length of the tracks for extended periods of time. These indentations cause the fore and aft movement of the seat to become rough and eventually impairs the fore and aft movement of the vehicle seat altogether.